Azernews.Az

By Alimat Aliyeva

The world’s most complex railway project is currently underway in southwestern China. This ambitious line, already hailed as one of the most technically challenging in railway history, is being constructed under extreme natural conditions, cutting through mountain ranges, seismic zones, and remote, hard-to-reach areas, and is expected to be fully operational by 2030, AzerNEWS reports.

Spanning 330 kilometers, the Dali–Ruili railway is set to transform transportation in the mountainous western region of Yunnan Province and strengthen China’s connectivity with South and Southeast Asia.

Completion of this project will mark a major milestone in global railway engineering. The section from Dali to Baoshan, a distance of 133 kilometers, now takes roughly an hour to traverse. Yet, due to the treacherous terrain, tens of thousands of workers labored for 14 years to build it, according to the South China Morning Post. By comparison, a similar line over flat, geologically stable ground could be completed in just three years.

The China Railway Group, one of the world’s largest construction and engineering contractors, explained that the railway passes through steep mountains, deep valleys, tectonically active zones, and unstable fractured rock. Builders had to avoid major fault lines and cross four large rivers, necessitating dozens of technically complex bridges and tunnels — 34 bridges and 21 tunnels in total.

One of the most formidable challenges was managing an enormous influx of groundwater. During construction, water gushed into the tunnels in a volume equivalent to 156,000 standard swimming pools, forcing workers to operate underwater for extended periods.

“This is the most difficult railway in the world to build,” noted a post on the Yunnan Provincial government’s social media account.

Experts say the Dali–Ruili line isn’t just an engineering feat; it also represents a leap forward in railway technology, showcasing innovative tunnel-boring techniques, high-precision bridge construction, and advanced safety measures in earthquake-prone regions. Once completed, the railway could become a model for future infrastructure projects in similarly extreme environments around the globe.